#region License block : MPL 1.1/GPL 2.0/LGPL 2.1
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the FreeCL.Net library.
 *
 * The Initial Developer of the Original Code is 
 *  Oleksii Prudkyi (Oleksii.Prudkyi@gmail.com).
 * Portions created by the Initial Developer are Copyright (C) 2005-2008
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
#endregion
 
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Diagnostics.CodeAnalysis;

namespace FreeCL.RTL
{
	/// <summary>
	/// Description of CryptoTools.	
	/// </summary>
	public static class CryptoTools
	{
		[SuppressMessage("Microsoft.Naming", "CA1705:LongAcronymsShouldBePascalCased", MessageId="Member")]
		public static string EncryptStringWith3DES(string data, string key, string iv)
		{
			UnicodeEncoding unicode = new UnicodeEncoding();
			Byte[] Bytes = unicode.GetBytes(data);
			
			MemoryStream mem = new MemoryStream(100);
			TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();					
			
			Byte[] KeyBytes = unicode.GetBytes(key);
			Byte[] tmpBytes = new Byte[16];
			Array.Copy(KeyBytes, tmpBytes, KeyBytes.Length < 16 ? KeyBytes.Length : 16);
			KeyBytes = tmpBytes;

			if(tdes.ValidKeySize(KeyBytes.Length*8))
				System.Diagnostics.Debug.WriteLine("Key size valid");	
			if(TripleDESCryptoServiceProvider.IsWeakKey(KeyBytes))
				System.Diagnostics.Debug.WriteLine("Key weak");	
			
			CryptoStream CrStream = new CryptoStream(mem, tdes.CreateEncryptor(KeyBytes, unicode.GetBytes(iv)), CryptoStreamMode.Write);
			
			for(int i = 0; i < Bytes.Length; i++)
				CrStream.WriteByte(Bytes[i]);

			CrStream.FlushFinalBlock(); 
			
			string result = Convert.ToBase64String(mem.GetBuffer(), 0, (int)mem.Length);
			CrStream.Dispose();
			return result;
		}

		[SuppressMessage("Microsoft.Naming", "CA1705:LongAcronymsShouldBePascalCased", MessageId="Member")]
		public static string DecryptStringWith3DES(string data, string key, string iv)
		{
			UnicodeEncoding unicode = new UnicodeEncoding();			
			Byte[] Bytes = Convert.FromBase64String(data);
			
			MemoryStream mem = new MemoryStream(100);
			TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();					
			
			Byte[] KeyBytes = unicode.GetBytes(key);
			Byte[] tmpBytes = new Byte[16];
			Array.Copy(KeyBytes, tmpBytes, KeyBytes.Length < 16 ? KeyBytes.Length : 16);
			KeyBytes = tmpBytes;
			
			if(tdes.ValidKeySize(KeyBytes.Length*8))
				System.Diagnostics.Debug.WriteLine("Key size valid");	
			if(TripleDESCryptoServiceProvider.IsWeakKey(KeyBytes))
				System.Diagnostics.Debug.WriteLine("Key weak");	
			CryptoStream CrStream = new CryptoStream(mem, tdes.CreateDecryptor(KeyBytes, unicode.GetBytes(iv)), CryptoStreamMode.Write);
			
			for(int i = 0; i < Bytes.Length; i++)
				CrStream.WriteByte(Bytes[i]);

			CrStream.FlushFinalBlock(); 

			string result = unicode.GetString(mem.GetBuffer(), 0, (int)mem.Length);			
			CrStream.Dispose();
			return result;
		}

		static MACTripleDES mac3des = new MACTripleDES(new Byte[16]{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16});

		[SuppressMessage("Microsoft.Naming", "CA1705:LongAcronymsShouldBePascalCased", MessageId="Member")]
		public static Int64 GetHashByMACTripleDES(string data)
		{
			UnicodeEncoding unicode = new UnicodeEncoding();
			Byte[] Bytes = unicode.GetBytes(data);
			
			byte[] result = mac3des.ComputeHash(Bytes);
			return BitConverter.ToInt64(result, 0);
		}

		
	}
}
